1. Field
The presently disclosed subject matter relates to vehicle lighting devices and vehicle lamps including decorative lighting devices and lamps, and more particularly to vehicle decorative lighting devices having a high visibility and a favorable light distribution, which can be incorporated along an outer periphery of a vehicle lamp. Thus a vehicle lamp that includes the decorative lighting device or devices can have a high visual quality which can emit harmonious light with respect to other lighting devices or lamps. The decorative lighting lamps can be used as a position lamp when the vehicle lamps are used as a headlight.
2. Description of the Related Art
Various vehicle lamps, including decorative lighting devices that form secondary light distributions, are known as a vehicle lamp, including headlights. For example, a conventional illumination device for vehicles, which can be incorporated into a headlight, is disclosed in Patent Document No. 1 (U.S. Pat. No. 5,984,497).
FIG. 12a is a schematic top view showing a conventional headlight including an illumination device which is formed in a rectangular shape, and FIG. 12b is a schematic cross-sectional side view showing the conventional headlight of FIG. 12a in which the illumination device is not shown, and both of which are disclosed in Patent Document No. 1.
The conventional headlight includes: a housing 10 having a light outlet opening; a reflector 12 arranged in the housing 10; a first light source 14, which is formed as an incandescent lamp or a gas discharge lamp, inserted in the reflector 12; a disk 16 being a light-permeable member and covering the light outlet opening of the housing 10; and a light guide element 20 emitting light as seen in a light outlet direction 18 of the headlight and being arranged on the disk 16 or on an edge of the housing 10.
FIG. 13 is a schematic view depicting the light guide element 20, which is used for the conventional headlight shown in FIG. 12a. The light guide element 20 includes: a second light source 24; a reflector 26 formed in an ellipsoidal shape, in which a first focal point is located at the second light source 24 and a second focal point is located at an inlet end 22 of light guiding fibers 28 in order to concentrate light emitted from the second light source 24 at the inlet end 22; and a part of an exterior surface 30 of the light guide element 20 configured to emit the light emitted from the second light source 24.
Accordingly, the conventional headlight may form a light distribution pattern such as a low beam, a high beam and the like using light emitted from the first light source 14 and the reflector 12. The light guide element 20 incorporated into the housing 10 of the headlight may provide a secondary light distribution pattern such as a side marker lamp using the light emitted from the second light source 24 and the exterior surface 30.
However, the light guiding fibers 28 used for the light guide element 20 may be a member for transmitting light from the inlet end 22 to an outlet end in nature, and may not be suitable for emitting light from an exterior surface thereof. Therefore, it may be difficult for the light guide element 20 to maintain at a high light-emitting efficiency. To improve this situation, a high power bulb may be used as the second light source 24, and reflector 26 may also be used to concentrate the light emitted from the second light source 24 at the inlet end 22 of the light guiding fibers 28 as shown in FIG. 13.
In these cases, because a light source portion including the high power bulb and the reflector 26 may become a large and complex structure, the headlight including the illumination device that uses the light guide element 20 may also become a large and complex structure. In addition, a power consumption of the illumination device using the light guide element 20 may become high, and also the light source portion may generate a large amount of heat.
Moreover, when an LED (light-emitting diode) light source or an HID (high-intensity discharge) lamp is used as the first light source 14 for the headlight, the headlight may emit a bluish white light. On the other hand, the light guide element 20 may emit a reddish white light when a high power incandescent lamp is used as the second light source 24. Accordingly, the conventional illumination device that is composed of the light guide element 20 may not emit light that is harmonious with light emitted from the headlight.
Furthermore, because a general shape of the light guiding fibers 28 used for the light guide element 20 may be circular, the exterior surface 30 that emits light as the conventional illumination device may also become a rounded surface. Thus, when the light guide element 20 is incorporated into the housing 10 of a headlight so as to emit light from the exterior surface 30, because a limited shape of the exterior surface 30 of the light guide element 20 may reduce possibilities for design with respect to the headlight including the illumination device, the conventional structure for the headlight including the illumination device may cause disfigurement, and also may cause difficulties in workability.
The above-referenced Patent Documents and additional Patent Documents are listed below and are hereby incorporated with their English specifications and abstracts in their entireties.    1. Patent Document No. 1: U.S. Pat. No. 5,984,497    2. Patent Document No. 2: U.S. patent application Ser. No. 13/162,151    3. Patent Document No. 3: U.S. patent application Ser. No. 13/284,859    4. Patent Document No. 4: U.S. patent application Ser. No. 13/229,663    5. Patent Document No. 5: co-assigned U.S. patent application Ser. No. 13/358,500    6. Patent Document No. 6: U.S. patent application Ser. No. 12/016,672
The disclosed subject matter has been devised to consider the above and other problems, characteristics and features. Thus, exemplary embodiments of the disclosed subject matter can include vehicle decorative lighting devices which can provide a favorable light distribution having a high visibility and a high visual quality with a simple structure, and which can expand possibilities for design so as to be able to harmonize with various vehicle lamps including a vehicle decorative lighting device.
In addition, exemplary embodiments of the disclosed subject matter can include vehicle decorative lighting devices which can emit various color lights using an LED light source having a low power consumption such that the lighting devices can be incorporated into various vehicle lamps such as a headlight, a turn signal lamp, a stop lamp, etc. In this case, when the vehicle lamp is a headlight such that a white LED light source or an HID bulb is used as a light source, the vehicle decorative lighting device can emit a harmonious white light with light emitted from the headlight so as to be usable as a position lamp and the like. Also, when the vehicle lamp is configured as a stop lamp such that a red LED light source is used as a light source, the vehicle decorative lighting device can emit a harmonious red light with light emitted from the stop lamp so as to be usable as a tail lamp, etc.